半导体与导体、绝缘体的区别是什么？
How do semiconductors differ from conductors and insulators?
导体价带与导带重叠、电阻极小；绝缘体带隙很宽、电子难以跃迁；半导体的带隙介于两者之间（硅约 1.1 eV），升温或掺杂后导电性显著增强。正是这种可调性使硅成为集成电路的基础。
Conductors have overlapping valence and conduction bands with tiny resistance; insulators have a wide band gap that blocks electron promotion; semiconductors sit between (silicon ~1.1 eV) and conduct far better when heated or doped. This tunability makes silicon the basis of integrated circuits.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
《材料科学基础》（胡赓祥）
Fundamentals of Materials Science (Hu Gengxiang)
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787313024800（豆瓣书目条目: 材料科学基础）
#半导体 #带隙 #掺杂
什么是纳米材料？
What are nanomaterials?
纳米材料的尺寸在1到100纳米之间，此时表面效应和量子效应变得显著，使材料表现出特殊的光、电、力学性能。它们用于催化剂、药物和涂层等领域。
Nanomaterials have dimensions between 1 and 100 nanometers, where surface and quantum effects become significant, giving special optical, electrical, and mechanical properties. They are used in catalysts, medicine, and coatings.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#纳米 #尺寸效应 #材料
什么是半导体材料？
What are semiconductor materials?
半导体的导电性介于导体和绝缘体之间，最常见的是硅和锗。通过掺入少量杂质可精确控制其导电性，是芯片和太阳能电池的基础。
Semiconductors have conductivity between that of conductors and insulators, with silicon and germanium being the most common. Adding tiny amounts of impurities precisely controls their conductivity, forming the basis of chips and solar cells.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#半导体 #硅 #芯片
铜氧化物高温超导体特别在哪里？
What is special about copper-oxide high-temperature superconductors?
Bednorz 与 Müller 在 1986 年发现镧钡铜氧在远高于传统极限的温度下出现零电阻，打破了 BCS 理论预期，开启高温超导研究。Tinkham 的《超导导论》系统论述了铜酸盐的奇异相图。
Bednorz and Müller found in 1986 that lanthanum barium copper oxide loses resistance far above the conventional limit, breaking BCS expectations and launching high-Tc research. Tinkham's 'Introduction to Superconductivity' surveys the cuprates' strange phase diagram.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
Bednorz 与 Müller 1986 年论文（1987 诺奖）；Tinkham《超导导论》
Bednorz & Müller (1986, Nobel 1987); Tinkham, Introduction to Superconductivity
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-0-486-134727-2 (2012, Dover)
#高温超导 #铜氧化物 #BCS
热电材料如何实现热与电的直接转换？衡量其效率的关键参数是什么？
How do thermoelectric materials directly convert heat and electricity, and what parameter governs their efficiency?
热电材料利用塞贝克效应（温差产生电压）和帕尔帖效应（通电产生温差）实现热-电互转。其转换效率由无量纲优值 ZT = S²σT/κ 决定，其中 S 为 Seebeck 系数、σ 电导、κ 热导。提高 ZT 需同时增大电输运、抑制热导（如纳米结构化降低晶格热导），这是材料设计的核心矛盾。
Thermoelectric materials exploit the Seebeck effect (voltage from a temperature difference) and Peltier effect (temperature difference from current) for direct heat–electricity conversion. Efficiency is set by the dimensionless figure of merit ZT = S²σT/κ, where S is the Seebeck coefficient, σ the electrical conductivity, and κ the thermal conductivity. Raising ZT requires enhancing electrical transport while suppressing heat conduction (e.g., via nanostructuring), the central design trade-off.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#热电材料 #塞贝克效应 #优值ZT #热电转换
均相催化的催化循环通常包含哪些基元步骤？以 Wilkinson 催化剂为例。
What elementary steps make up a homogeneous catalytic cycle, using the Wilkinson catalyst as an example?
均相催化循环一般包括配体解离、底物配位、插入/迁移以及产物解离等基元步骤，循环再生活性中心。Wilkinson 催化剂 RhCl(PPh₃)₃ 催化的烯烃氢化即依次经历膦配体解离、烯烃配位、氧化加成 H₂、迁移插入与还原消除。每个基元步骤都有确定的速率与立体化学后果。
A homogeneous catalytic cycle generally comprises elementary steps such as ligand dissociation, substrate coordination, insertion/migration, and product dissociation, regenerating the active site. In RhCl(PPh₃)₃ (Wilkinson's catalyst) hydrogenation of alkenes, these are phosphine dissociation, alkene coordination, oxidative addition of H₂, migratory insertion, and reductive elimination. Each step has a defined rate and stereochemical outcome.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
《美国化学会志》(JACS) 催化机理研究；R. H. Crabtree, The Organometallic Chemistry of Transition Metals
R. H. Crabtree, The Organometallic Chemistry of Transition Metals; JACS, catalytic mechanism studies
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL11857384W：The organometallic che
#均相催化 #催化循环 #Wilkinson #氢化
为什么纳米材料常表现出特殊性质？
Why do nanomaterials often show special properties?
当材料尺寸降到纳米尺度（1–100 nm），表面原子比例剧增，比表面积巨大，量子限域效应也开始显现。这使纳米颗粒的催化活性、颜色和熔点等与块体明显不同，例如金纳米颗粒可呈红色。这类特性推动了催化、医药等领域发展。
When materials shrink to the nanoscale (1–100 nm), the fraction of surface atoms and surface area surge, and quantum confinement appears. This makes nanoparticles differ from bulk in catalytic activity, color, and melting point—gold nanoparticles can look red, for instance. Such traits advance catalysis and medicine.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
《材料科学基础》（胡赓祥）
Fundamentals of Materials Science (Hu Gengxiang)
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787313024800（豆瓣书目条目: 材料科学基础）
#纳米材料 #表面效应 #量子限域
钙钛矿太阳能电池为什么能实现高光电转换效率？核心限制因素是什么？
Why can perovskite solar cells achieve high power-conversion efficiency, and what is their main limiting factor?
有机-无机杂化钙钛矿（如 CH₃NH₃PbI₃）具有长载流子扩散长度、高光吸收系数和可调控的带隙，使光生电子-空穴对能高效分离与收集。溶液法制备成本低、可调组分带隙适合叠层电池。主要限制是铅的毒性和在湿热、光照下的长期稳定性问题。
Hybrid organic–inorganic perovskites such as CH₃NH₃PbI₃ have long carrier diffusion lengths, high absorption coefficients, and tunable band gaps, letting photogenerated electron–hole pairs separate and be collected efficiently. Solution processing is cheap, and tunable gaps suit tandem cells. Main limits are lead toxicity and poor long-term stability under heat, humidity, and light.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
《Nature Photonics》钙钛矿综述；中国科学院半导体研究所
Nature Photonics, perovskite reviews; Nature Energy, stability studies
#钙钛矿 #太阳能电池 #载流子 #带隙
三元锂离子电池正极材料（如 NMC）的化学计量如何影响性能？
How does the stoichiometry of ternary lithium-ion cathode materials such as NMC affect performance?
NMC 正极通式为 LiNiₓMnᵧCo_{1−ₓ−ᵧ}O₂（x+y+z=1），镍提升比容量，锰稳定结构并改善安全，钴提高电导与倍率性能。提高镍含量（如 NMC811）可增加能量密度，但会加剧阳离子混排与界面副反应，降低循环寿命。因此材料设计是在容量、稳定性与成本之间的多目标权衡。
NMC cathodes have the formula LiNiₓMnᵧCo_{1−ₓ−ᵧ}O₂ (x+y+z=1), where nickel boosts capacity, manganese stabilizes the structure and safety, and cobalt improves conductivity and rate capability. Raising nickel content (e.g., NMC811) increases energy density but worsens cation mixing and interfacial side reactions, shortening cycle life. Material design thus trades off capacity, stability, and cost.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#锂离子电池 #正极 #NMC #镍锰钴
什么是复合材料？举例说明。
What are composite materials? Give an example.
复合材料由两种或以上性能不同的材料组合，取长补短，获得单一材料没有的综合性能。例如玻璃纤维增强塑料（玻璃钢）以树脂为基体、玻璃纤维为增强相，质轻而强度高。碳纤维复合材料广泛用于航空与运动器材。
A composite combines two or more materials with different properties to gain synergies no single material has. Glass-fiber-reinforced plastic (fiberglass) uses resin as matrix and glass fibers as reinforcement—light yet strong. Carbon-fiber composites are widely used in aviation and sports gear.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
《材料科学基础》（胡赓祥）
Fundamentals of Materials Science (Hu Gengxiang)
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787313024800（豆瓣书目条目: 材料科学基础）
#复合材料 #玻璃钢 #增强相
什么是陶瓷材料？
What are ceramic materials?
陶瓷是无机非金属材料，通常由粘土高温烧制而成，耐高温、硬度高但较脆。现代陶瓷还用于牙齿、发动机部件和电子产品。
Ceramics are inorganic nonmetallic materials, usually made by firing clay at high temperature; they resist heat and are hard but brittle. Modern ceramics are also used in teeth, engine parts, and electronics.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#陶瓷 #无机 #耐高温
陶瓷材料有什么典型特性？
What are the typical properties of ceramic materials?
陶瓷多由金属与非金属元素的离子/共价化合物（如氧化铝、硅酸盐）构成，硬度高、耐高温、耐腐蚀且绝缘。缺点是脆性大、抗冲击差。它们广泛用于刀具、耐火材料和电子基板。
Ceramics are mostly ionic/covalent compounds of metals and nonmetals (e.g., alumina, silicates); they are hard, heat-resistant, corrosion-resistant, and insulating. Their drawback is high brittleness and poor impact resistance. They are widely used in cutting tools, refractories, and electronic substrates.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
《材料科学基础》（胡赓祥）
Fundamentals of Materials Science (Hu Gengxiang)
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787313024800（豆瓣书目条目: 材料科学基础）
#陶瓷 #耐高温 #脆性
什么是聚合物（高分子）材料？
What are polymer (macromolecular) materials?
聚合物是由许多重复单元连接成的巨大分子，如塑料、橡胶和纤维。它们的性能取决于链的长短、排列和交联方式。
Polymers are huge molecules made of many repeating units, such as plastics, rubber, and fibers. Their properties depend on chain length, arrangement, and cross-linking.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#聚合物 #高分子 #塑料
超级电容器和传统锂离子电池在储能机制上有何不同？
How does the energy-storage mechanism of a supercapacitor differ from that of a conventional lithium-ion battery?
超级电容器通过电极/电解液界面的双电层静电吸附（或快速可逆的赝电容 redox）储能，充放电快、循环寿命长但能量密度低。锂离子电池依靠锂离子在正负极间的嵌入/脱嵌发生氧化还原反应储能，能量密度高但功率密度与倍率性能较低。二者常互补用于需要高功率与高能量的不同场景。
Supercapacitors store energy by electrostatic double-layer adsorption at the electrode–electrolyte interface (or fast pseudocapacitive redox), giving fast charge–discharge and long life but low energy density. Lithium-ion batteries store energy via redox-coupled intercalation of Li⁺, offering high energy density but lower power and rate capability. The two are complementary for high-power versus high-energy needs.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
《Nature Reviews Materials》电化学储能综述；美国化学会(ACS)能源 LETTERS
Nature Reviews Materials, electrochemical storage reviews; ACS Energy Letters
#超级电容器 #双电层 #锂离子电池 #储能
液晶（liquid crystal）处于什么状态？它为什么既像液体又能控制光的通过？
What state of matter is a liquid crystal, and why can it act like a liquid yet control the passage of light?
液晶是介于各向同性液体与晶体之间的中间态，分子可流动（像液体）却又保持一定的取向有序（像晶体）。其分子取向可被电场改变，从而旋转入射偏振光的偏振方向，这一性质正是液晶显示器（LCD）的工作原理。
A liquid crystal is an intermediate state between an isotropic liquid and a crystal: its molecules can flow like a liquid yet retain some orientational order like a crystal. An applied electric field can reorient the molecules, rotating the polarization of passing light—the principle behind liquid-crystal displays (LCDs).
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
英国皇家化学会（RSC）材料化学综述；P. G. de Gennes《液晶物理学》
Royal Society of Chemistry (RSC) materials reviews; P. G. de Gennes, 'The Physics of Liquid Crystals'
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL53665W：The physics of liquid cry
#液晶 #中间相 #取向有序 #显示器 #偏振
石墨烯（graphene）是什么结构？它为什么具有异常高的导电和导热性能？
What is the structure of graphene, and why does it have exceptionally high electrical and thermal conductivity?
石墨烯是单层碳原子以sp²杂化形成的二维蜂窝状六角晶格，每个碳原子贡献一个离域π电子。这些自由离域的电子可在平面内无阻碍高速移动，加上极强的C-C键和高效的声子传输，使其兼具超高导电性与导热性，2004年由盖姆和诺沃肖洛夫首次分离并获2010年诺贝尔奖。
Graphene is a single layer of carbon atoms in a two-dimensional honeycomb lattice with sp² hybridization, each atom contributing one delocalized π electron. These delocalized electrons move freely and rapidly in the plane, and the strong C-C bonds enable efficient phonon transport, giving both extraordinary electrical and thermal conductivity; it was first isolated by Geim and Novoselov in 2004, earning the 2010 Nobel Prize.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Housecroft & Sharpe,《Inorganic Chemistry》第5版,Pearson,2018
C. E. Housecroft and A. G. Sharpe, Inorganic Chemistry, 5th ed., Pearson, 2018
#石墨烯 #二维材料 #sp²杂化 #导电 #诺沃肖洛夫
合金为什么往往比纯金属更硬？
Why are alloys often harder than pure metals?
合金是在金属中加入其他元素形成的混合物，异种原子破坏了纯金属规则的层状排列，使位错滑移受阻。原子尺寸差异和固溶强化提高了硬度和强度，例如钢比纯铁坚硬得多。这解释了为何工程少用纯金属。
Alloys mix a metal with other elements; foreign atoms disrupt the regular layered arrangement of pure metal, hindering dislocation slip. Size mismatch and solid-solution strengthening raise hardness and strength—steel is far harder than pure iron. This is why engineering rarely uses pure metals.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
《材料科学基础》（胡赓祥）
Fundamentals of Materials Science (Hu Gengxiang)
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787313024800（豆瓣书目条目: 材料科学基础）
#合金 #固溶强化 #位错
什么是碳纤维？
What is carbon fiber?
碳纤维是由碳原子构成的高温处理细丝，又轻又硬、强度高，常用于飞机、赛车和运动器材。它常与树脂结合成复合材料使用。
Carbon fiber is a fine filament of carbon atoms treated at high temperature; it is light, stiff, and strong, used in aircraft, race cars, and sports gear. It is often combined with resin as a composite.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#碳纤维 #复合材料 #轻量
催化剂表面的吸附有哪两种类型？它们对催化有何意义？
What are the two main types of adsorption on catalyst surfaces, and why do they matter for catalysis?
物理吸附由范德华力引起，可逆、无电子转移、活化能低；化学吸附涉及表面与吸附质间形成化学键，有电子共享或转移，具选择性且较稳定。催化反应通常依赖适中的化学吸附——过强会使表面中毒，过弱则无法活化反应物。因此吸附强度是催化剂设计的关键。
Physisorption arises from van der Waals forces and is reversible, non-specific, and low in activation energy; chemisorption involves bond formation with electron sharing or transfer and is selective and more stable. Catalysis generally relies on moderate chemisorption—too strong poisons the surface, too weak fails to activate reactants. Adsorption strength is therefore central to catalyst design.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
《物理化学》(傅献彩, 第五版) 表面现象章；IUPAC（催化术语）, 2011
IUPAC (Manual on Catalyst Characterization, 2011); Atkins & de Paula, Physical Chemistry, surface chapter
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-0-19-884781-6 (11th ed., Oxford University Pres
#物理吸附 #化学吸附 #催化表面 #活化
陶瓷为什么又硬又脆？
Why are ceramics hard yet brittle?
陶瓷多为离子或共价网络，键强且方向性强，故硬度高、熔点高；但位错难以滑移、裂纹一旦萌生便迅速扩展，所以缺乏塑性而易脆断。Callister 的《材料科学与工程》用键合与缺陷解释了这一点。
Ceramics are ionic or covalent networks with strong, directional bonds, giving high hardness and melting point; but dislocations cannot easily slip and cracks propagate fast, so they lack ductility and fail brittlely. Callister explains this via bonding and defects.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 3 条独立证据
来源 · Source
Callister《材料科学与工程基础》
Callister, Materials Science and Engineering: An Introduction
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-1-119-45520-2 (Global Ed.) / 978-1-119-45391-8 · 核验依据 2 ISBN 9781292247137 · 核验依据 3 ISBN 9781641950565 (2019)
#陶瓷 #脆性 #离子键
水泥是怎么变硬的？
How does cement harden?
水泥加水后，其中的硅酸盐和铝酸盐与水发生水化反应，生成坚硬的结晶物质把砂和石粘在一起。这个过程会放热并需要一定时间。
When water is added to cement, its silicates and aluminates react with water in hydration, forming hard crystalline substances that bind sand and gravel. The process releases heat and takes time.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#水泥 #水化 #硬化
沸石（zeolite）为什么能作催化剂和离子交换剂？其结构关键是什么？
Why can zeolites serve as catalysts and ion exchangers, and what is the key to their structure?
沸石是微孔铝硅酸盐骨架，内部具有均匀、规则的纳米级孔道和空腔。这些孔道能选择性吸附特定大小的分子（分子筛效应）并提供限域反应空间，骨架上的负电荷可由可交换的阳离子平衡，从而兼具择形催化与离子交换能力。
Zeolites are microporous aluminosilicate frameworks with uniform, regular nano-sized channels and cavities. These pores selectively adsorb molecules of certain sizes (molecular-sieving) and provide confined reaction space, while negative charges on the framework are balanced by exchangeable cations, giving zeolites both shape-selective catalysis and ion-exchange ability.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
国际沸石协会（IZA）结构数据库；潘履让《固体催化剂》
International Zeolite Association (IZA) Structure Database; Pan Lürang, 'Solid Catalysts'
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL38118947W：Solid Base Catalysts（首
#沸石 #分子筛 #铝硅酸盐 #孔道 #离子交换
石墨为什么能作为锂离子电池的负极材料？嵌锂过程发生了什么？
Why can graphite serve as a lithium-ion battery anode, and what happens during lithium intercalation?
石墨层状结构层间有空隙，可可逆地插入锂离子形成插层化合物 LiₓC₆，理论比容量约 372 mAh/g。嵌锂时锂离子进入层间并储存于石墨烯片层之间，电子同时进入碳的 π 共轭体系，过程保持骨架完整。脱锂时反应逆向进行，实现充放电循环。
Graphite's layered structure has gaps between sheets that reversibly accept lithium to form the intercalation compound LiₓC₆, with a theoretical capacity near 372 mAh/g. On lithiation, Li⁺ enters between graphene layers while electrons enter the carbon π system, leaving the framework intact. Delithiation reverses the process, enabling charge–discharge cycling.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-03
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《电化学原理》(李荻) 二次电池章；美国化学会(ACS)能源 LETTERS
ACS Energy Letters, anode materials; Journal of The Electrochemical Society
独立核验依据 · Independent verification: 核验依据 1 ISBN 9787811244168（豆瓣书目条目: 电化学原理）；本条出处含多部著作，此标识只担保上面点名的这
#石墨负极 #嵌锂 #插层化合物 #锂离子电池
形状记忆合金（如镍钛诺 Nitinol）为什么被扭曲后能“记住”原来的形状？
Why can shape-memory alloys such as Nitinol 'remember' their original shape after being deformed?
以镍钛诺（NiTi）为代表的形状记忆合金在低温下可发生可逆的马氏体相变，此时易被扭曲成新形状。加热回到较高温度的奥氏体相时，材料会自动恢复之前在高温下定型的“记忆”形状，这种效应源于晶体相变的可逆性。
Shape-memory alloys like Nitinol (NiTi) undergo a reversible martensitic phase transformation at low temperature, when they can be easily deformed into a new shape. Upon heating back to the higher-temperature austenite phase, the material spontaneously recovers the 'remembered' shape set at high temperature; the effect arises from the reversibility of the crystal-phase transition.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-03
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材料研究学会（MRS）形状记忆合金综述；大冢和韦曼《形状记忆材料》（Shape Memory Materials, Cambridge University Press, 1998）
Materials Research Society (MRS) reviews on shape-memory alloys; K. Otsuka & C. M. Wayman, 'Shape Memory Materials' (Cambridge University Press, 1998)
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL19901882W：Shape memory materials
#形状记忆合金 #镍钛诺 #马氏体 #相变 #奥氏体
合金是什么？
What is an alloy?
合金是由两种或更多种金属（或金属与非金属）熔合而成的材料，性能往往比纯金属更好。例如钢是铁和碳的合金，比纯铁更硬更结实。
An alloy is a material made by mixing two or more metals, or a metal with a nonmetal, usually by melting. Its properties are often better than pure metals. For example, steel is an alloy of iron and carbon and is harder than pure iron.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#合金 #钢 #金属
橡胶为什么会老化变黏？
Why does rubber age and become sticky?
橡胶长期受阳光、氧气和高温作用，分子链发生断裂或交联，弹性下降并变黏或变脆。加入防老剂可以延缓这一过程。
Under long exposure to sunlight, oxygen, and heat, rubber's molecular chains break or cross-link, losing elasticity and becoming sticky or brittle. Adding anti-aging agents slows this process.
难度 入门 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#橡胶 #老化 #氧化
玻璃是怎么做出来的？
How is glass made?
普通玻璃由沙子（二氧化硅）、纯碱和石灰石高温熔融后冷却而成。它冷却时不结晶，形成透明的非晶态固体。
Ordinary glass is made by melting sand (silica), soda ash, and limestone at high temperature and then cooling. It does not crystallize on cooling, forming a transparent non-crystalline solid.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#玻璃 #二氧化硅 #非晶
不锈钢为什么不容易生锈？
Why does stainless steel resist rusting?
不锈钢中加入了铬等元素，会在表面形成一层致密的氧化膜，把金属与外界隔开。这样它比普通钢更耐腐蚀。
Stainless steel contains elements like chromium that form a dense oxide film on the surface, separating the metal from the environment. This makes it much more corrosion-resistant than ordinary steel.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#不锈钢 #铬 #防锈